Worm-gear



D. FITZPATRICK.

WORM GEAR.

LICATIoN FILED 1AN.4.1918.

APP

RENEWED SEPT. B, 1920.

Patented Nov. '9, 1920.

4UNITED sTAres PATENT OFFICE.v

DAVID FITZPA'IRICK, OF CLEVELAND, OHIO, ASSGNOR T0 THE CLEVELAND WORM AND GEAR COMPANY, 0F CLEVELAND, OHIO, A CORPORATION OF OI-II.

WORM- GEAR.

Specification of Letters Patent.

Patented Nov. 9.192%

Application led January 4, 1918, Serial No. 210,388. Renewed September 8, 1920. Serial No. 409,938.

To all whom it may concern Be it known that I, DAVID FITZPATBICK, a subject of Great Britain, and resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Worm-Gears, of which the following is a specification.

My invention relates in general to a wheel having an outer ring formed of material dierent from that of the body or center of the wheel and relates more particularly to a modified form of the gear wheel that is shown in my co-pendng application, Serial No. 77,361 filed February 10, 1916.

The object of this invention is to produce a wheel comprising a oentervof relatively strong material such as cast iron having a peripheral groove with substantially continuous shoulders and suitable passages communicating with said groove and an outer ring of relatively weak material such as bronze or similar material that is cast onto the center and permanently secured thereto.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying drawings and in part will be more fully set forth in the following particular description of one form of mechanism embodying my invention, and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.V

In the accompanying drawings:

Figure 1 is a side elevation partly in section of a gear wheel embodying my invention.

Fig. 2 is a front view partly in sectionl of the gear wheel.

The center A of the wheel may be of cast iron, malleable iron, steel or suitable alloy. rlhe rim or periphery of the center is provided with a central annular groove B. This groove B is relatively narrow and is limited by sharply defined shoulders C that are practically continuous except for small transverse slots D which are spaced at considerable intervals to provide additional anchorage for the cast metal ring. A plurality of locking loops or openings E are provided in the rim and communicate with the groove at each end. These loops may communicate with the side of the wheel through the side of the wheel preferably near the lower or innermost portion of the loop. One such exterior opening vis provided for each of the locking loops.

A ring H of relatively weak anti-frictionv metal such as bronze or similar alloy is cast around the periphery of the wheel. The metal flows into the locking loops or openings and also into the side passages and securely anchors the ring into the center or core.

After the ring has been cast in place suitable teeth are cut in the periphery of the ring which may be of any desired character. My invention being particularly adapted for use with worm gears but spur gears or any other type may be made.

The shoulders formed by the annular groove hold the ring securely against lateral movement, and the locking loops prevent any creeping or circumferential movement. The loops are further reinforced by the lateral plug of metal that extends through the side opening provided in the rim. This opening also serves the purpose of preventing the formation of air pockets when the ring is cast. The bronze is cast onto the core in the usual way at a single casting operation and an extremely strong and rigid construction is provided with a limited use of the relatively expensive bronze or other anti-friction metal.

While I have shown and described, and have pointed out in the annexed claims, certain novel features of my invention, it will be understood that various omissions, substitutions and changesiin the form and details of the device illustrated and'in its operation may be made b those skilled in the art without departing from the spirit of the invention.

Having thus described my invention, I claim:

1. A gear wheel having a center of comparatively strong met-al with an annular shoulder on its outer face and a cast ring of comparatively weak anti-friction material on said center in engagement with said shoulder, one of said parts having also projections entering openings in the other and extending toward the axis.

2. A gear having a center of compara" tively strong metal with an annular groove on its outer face and a plurality of openings in the rim communicating with said groove,

and a cast ring of comparatively Weak antitrlctlon material on said center 1n engagement with said groove,' said cast ring having projections entering said openings.

3. A gear having a center of cast iron with an ,annular shoulder on its outerface and a plurality of openings extending to-V ward, the axis, said openings communicating i with a side of the center through a passage approximately parallel to the axis, and a cast ringpof comparatively Weal-anti-fric tion material. on said center inengagement With said shoulder, said ring having proi jections entering .the openingszin the said 

